Nitrate esters of corticoid compounds and pharmaceutical applications thereof

ABSTRACT

Compounds of the formula 
                         
and use of the compounds as medicaments.

This application is a divisional of prior application Ser. No.10/462,637, filed Jun. 17, 2003, now U.S. Pat. No. 7,056,905 B2; whichis a divisional of application Ser. No. 09/269,729, filed Apr. 2, 1999,now U.S. Pat. No. 6,610,676 B1, which in turn was a National Stageapplication of International Application No. PCT/EP97/05426, filed Oct.2, 1997. The disclosures of the prior applications are herebyincorporated by reference herein in their entirety.

The present invention relates to preparation of new corticoid compounds.

In particular it relates to steroid-structured compounds havinganti-inflammatory, immunodepressive and angiostatic activities (theso-called steroid anti-inflammatory drugs).

The compounds according to the present invention are therapeuticallyuseful in the treatment of pathologic conditions where generallycorticosteroid (corticoids) preparations are used, but with increasedbenefits.

This represents an unexpected advantage over the known corticoidsproducts. In fact, by taking into account the various definedtherapeutic uses of a specific product, it is always possible, with thenew products of the present invention, to find a better combination ofresults with respect to the known corticoids. Contrary to anyexpectation the products of the present invention are characterised bythe fact that they show an improved therapeutic profile: high activitycombined with low side-effects.

Corticoids are well known as a first-choice pharmacological measure inthe treatment of inflammatory disease. Drugs in this category—whichinclude, for example, hydrocortisone, cortisone, prednisolone,prednisone, fludrocortisone, desoxycorticosterone, methylprednisolone,triamcinolone, paramethasone, betametasone, dexamethasone, triamcinoloneacetonide, fluocinolone acetonide, beclomethasone, acetoxypregnelone,etc.—have marked pharmacotoxicological effects on various organs.Because of this, the clinical use and discontinued use thereof cause aseries of side effects some of which are very severe. See for exampleGoodman & Gilman: “The Pharmaceutical Basis of Therapeutics”, 9th Ed.,pages 1459–1465, 1996.

These toxic effects include:

-   -   those on bone which lead to changed cell metabolism and a high        frequency of osteoporosis;    -   those on the cardiovascular system which cause hypertensive        reactions;    -   those on the gastrointestinal tract which cause gastric damage.        See for instance Martindale: “The Extrapharmacopoeia”; 30th Ed.,        pages 712–723, 1993.

According to the above mentioned art it appears to be almost impossiblefor therapeutic activities to be separated from side effects, seeGoodman et al., as mentioned above, at page 1474.

Known in the art are non-steroid anti-inflammatory drugs either with orwithout acidic ending, see patents WO 94/04484, WO 94/12463, WO95/09831, WO 95/30641 for non-acidic ending and the patents thereinmentioned for those with acidic ending.

However, it should be noted that steroid compounds are completelydifferent from non-steroid compounds chemically, pharmacologically andbiochemically as the pharmaco-toxicological mechanism of action ofnon-steroid products is based on inhibition of one or morecyclo-oxygenases (COX), while steroid products have nothing to sharewith COX and have more complex pharmaco-toxicological mechanisms ofaction which have not yet been fully explained.

It is well known that these two groups of compounds are listed incompletely separate categories in international pharmacopoeias.

The applicant has surprisingly and unexpectedly found corticosteroids(corticoids) which are very effective, even superior to those in theknown art, and have, at the same time, a higher tolerance than the knowncorticoids as unexpectedly they do not cause the above side effects, orwhen they do, these are lower.

An object of the present invention are corticosteroids and their use asanti-inflammatory, immunosuppressive and angiostatic agents having thegeneral formula:B—X₁—NO₂or their esters or salts, where:B has the following structure:

where, in place of the hydrogens H in the CH group or two hydrogens H₂in the CH₂ group shown in the general formula, there may be thefollowing substituents:

-   at position 1–2: there may be a double bond;-   at position 2–3: there may be the following substituent:

-   at position 2: there may be Cl, Br;-   at position 3: there may be CO, —O—CH₂—C₂—Cl, OH;-   at position 4–5: there may be a double bond;-   at position 5–6: there may be a double bond;-   at position 6: there may be Cl, F, CH₃, —CHO;-   at position 7: there may be Cl;-   at position 9: there may be Cl, F;-   at position 11: there may be OH, CO, Cl;-   at position 16, there may be CH₃, OH, ═CH₂;-   at position 17: there may be OH, CH₃, OCO(O)_(ua)(CH₂)_(va)CH₃, or

where ua is an integer equal to 0 or 1, va is an integer from 0 to 4;

-   at positions 16–17: there may be the following groups

R and R′ are equal or different one from the other and may be hydrogenor linear or branched alkyls having from 1 to 4 carbon atoms, preferablyR=R′=CH₃;B Being a Corticosteroid Residue;R″ is —(CO-L)_(t)—(X)_(t1)—where t and t1 are integers equal or different one from the other andequal to 0 or 1, provided that they cannot be both equal to 0 when Bcontains no —OH groups; the bivalent bridging group L is selected from:(CR₄R₅)_(na)(O)_(nb)(CR₄R₅)_(n′a)(CO)_(n′b)(O)_(n″b)(CO)_(n′″b)(CR₄R₅)_(n″a)where na, n′a and n″a are equal or different one from the other and areintegers from 0 to 6, preferably from 1 to 3; nb, nb′, n″b and n′″b areequal or different one from the other and are integers equal to 0 or 1;R₄ and R₅ are equal or different one from the other and are chosen fromH, linear or branched alkyl having from 1 to 5 carbon atoms, preferablyfrom 1 to 3;

-   X is equal to X₀=0, NH, NR_(1c) where R_(1c) is a linear or branched    alkyl having from 1 to 10 C atoms; or equal to X₂ where X₂ is equal    to OH, CH₃, Cl, N(—CH₂—CH₃)₂, SCH₂F, SH,

-   X₁ is a bivalent connecting bridge chosen from:    -   YO        where Y is a linear or whenever possible branched C₁–C₂₀        alkylene, preferably having from 2 to 5 carbon atoms, or an        optionally substituted cycloalkylene having from 5 to 7 carbon        atoms;-   Y₁ selected from

where n_is an integer from 0 to 3;

where nf′ is an integer from 1 to 6, preferably from 2 to 4;

where R_(1f)=H, CH₃ and nf is an integer from 1 to 6, preferably from 2to 4.

The compounds which can be mentioned, and which are those preferred, arethe ones listed below where B can be obtained according to the knownprocesses of the art.

For example, the precursors and related processes described for examplein The Merck Index, 12th Ed. of 1996, herein incorporated by reference,can be mentioned as precursors and related processes. The precursors(according to the Merck nomenclature) include the following, where H₂,H, R, R′, R″ have the meaning as defined in the compounds listed below:budesonide, hydrocortisone, alclometasone, algestone, beclomethasone,betamethasone, chloroprednisone, clobetasol, clobetasone, clocortolone,cloprednol, cortisone, corticosterone, deflazacort, desonide,desoximetasone, dexamethasone, diflorasone, diflucortolone,difluprednate, fluazacort, flucloronide, flumethasone, flunisolide,fluocinolone acetonide, fluocinonide, fluocortyn butyl, fluocortolone,fluorometholone, fluperolone acetate, fluprednidene acetate,fluprednisolone, flurandrenolide, formocortal, halcinonide, halobetasolpropionate, halometasone, halopredone acetate, hydrocortamate,loteprednol etabonate, medrysone, meprednisone, methylprednisolone,mometasone furoate, parametasone, prednicarbate, prednisolone,prednisolone 25-diethylaminoacetate, prednisolone sodium phosphate,prednisone, prednival, prednylidene, rimexolone, triamcinolone,triamcinolone acetonide, 21-acetoxypregnenolone, cortivazol, amcinonide,fluticasone proprionate, mazipredone, tixocortol, triamcinolonehexacetonide.

The X₁ connecting bridges as above defined are obtainable by using themethods known in the art as indicated above or by modifing the knownmethods by introducing X₁ bridges when these are different from theconnecting bridges described in the listed patents, using processesknown in the art. Generally the connection between B and X₁ is, as seen,of an ester or amide type (NH or NR_(1c), as defined in X). Any wellknown synthetic route for forming these bonds can be used to form thisconnection.

In the case of esters, the most direct synthethic route includes:

reaction of acyl chlorides B—CO—Cl in halogen alcohols of theHO—Y_(a)—Cl, HO—Y_(a)—Br, HO—Y_(a)—I type, where Y_(a) is equal to Y orY₁ without the oxygen atom, in test conditions which are part of theknown art.

The reaction products of formula B—CO—O—Y—Cl(Br,I) can also be obtainedby reacting the sodium or potassium salts of salts acids B—CO—OH withdihalogen derivatives of the general formula Y_(a)Cl₂, Y_(a)Br_(a) orY_(a)I₂, ClY_(a)Br, ClY_(a)I, BrY_(a)I.

The reaction products are converted into the final products by reactingwith AgNO₃ in acetonitrile according to what is known in the literature.

The general scheme is as follows:B—CO—Cl+HO—Y_(a)—Br--->B—CO—O—Y_(a)—Br+AgNO₃--->B—X₁NO₂where X₁=Y_(a)O.

The general scheme may also be as follows:B—CO—ONa+Br₂Y_(a)--->B—CO—O—Y_(a)—Br+AgNO₃--->B—X₁NO₂where X₁=Y_(a)O.

In this case of amide, the synthetic sequence includes reaction of thesame acyl chlorides BCOC1 with aminoalcohols of the general formulaNH₂—Y_(a)—OH, NHR_(1c)—Y_(a)—OH to give amides of the general formula:B—CO—NH—Y_(a)—OH and B—CO—NR_(1c)—Y_(a)—OHaccording to known methods.

Reaction of these amides with halogenating agents such as, for examplePCl₅, PBr₃, SOCl₂, etc., gives the halogen derivatives of the generalformula:B—CO—NH—Y_(a)—Br(Cl) and B—CO—NR_(1c)—Y_(a)—Br(Cl).

The latter give the final products BX₁NO₂ by reacting with AgNO₃ inacetonitrile according to methods known in the literature.

-   -   The sequence may be represented as:

where Y_(a)O is X₁.

An alternative route to ester formation is reaction of the sodium orpotassium salts of the acids with the nitric esters of halogen alcoholsof the general formula:NO₂—O—Y_(a)—Cl (Br, I)to directly give the products of the invention.

The reaction scheme is as follows:B—CO—ONa+Br—Y_(a)—ONO₂--->B—CO—O—Y_(a)—ONO₂where Y_(a)O is X₁.

Other synthetic routes similar to those described above include those inwhich the dihalogen derivative Br₂Y_(a) is reacted with enolates. Thereaction products are then converted by reacting with AgNO₃ inacetonitrile according to the above reaction. The general scheme isshown for an —OH in group B, of the type —CH₂—OH, ═CH—OH, is as follows:

The processes to obtain these X₁ connecting groups are described inpatent application WO95/30641 herein incorporated by reference.

As said above the compounds of the invention of formula B—X₁—NO₂ ortheir pharmaceutical compositions, are used for the treatment ofdiseases in which the well known corticoids products are employed.

In particular, it can be specifically mentioned the use in respiratorydisorders, e.g. antiasthmatic, the use as antiarthritic, antipruritic,antipsoriatic, antieczematic; the use in vascular disorders, e.g. asangiostatic, the use in immunology disorders, e.g. as immunosoppressive.

The compounds, or their compositions, of the present invention can beadministered for example by oral, rectal (intestinal disorders),parenteral route or by local (dermal, topical, transdermal, ocular,inhalatory, etc.) application.

The following examples -are given only for illustrative purpose as anexplanation but not as a limitation of the present invention.

EXAMPLE 1 CHEMICAL SYNTHESIS Preparation of HydrocortisoneNitroderivative (HCN)

EXAMPLE 1A Preparation of Hydrocortisone (4-chloro)butanoate

4 portions of 4-chlorobutanoylchloride (0.32 ml×4) and triethylamine(0.3 g×4) were added in 24 hours to a solution of hydrocortisone (1 g)in CHCl₃ dried over P₂O₅, and stirred for 3 days. The solution wastreated with water, the organic phase was separated, dried (Na₂SO₄) anddeprived of the solvent at reduced pressure. The crude residue wasground with hexane and CH₂Cl₂ to give a white solid with a 53% yield byweight, which had a melting point (m.p.) of 155° C.

The product was characterised by mass spectometry: M⁺493.

¹H NMR (300 MHz CDCl₃): 0.95 (3H,s,CH₃), 1.45 (3H, s, CH₃), 2.12 (2H, t,CH₂ in 2), 2.6(2H, t, CH₂COO), 3.65 (2H, t, CH₂Cl), 4.45 (1H, m, CHOH),4.35 and 5.05 (2H, 2d, COCH₂O), 5.70 (1H, s, olefin H).

Preparation of Hydrocortisone (4-nitroxy)butanoate

AgNO₃ (0.2 g) was added to a solution ofhydrocortisone-4-chlorobutancate prepared as above (0.23 g) inacetonitrile (70 ml) and refluxed for 16 hours. The solution wasdeprived of the solvent at reduced pressure and chromatographed onsilica gel using a solution of ethyl acetate and CH₂Cl₂ (3:7) as aneluant.

Cortisone 4-nitroxybutanoate was recovered from the head fractions.

The product was characterised by ¹HNMR (300 MHz CDCL₃): 0,95 (3H, s,CH₃), 1.45 (3H, s, CH₃), 2.12 (2H, t, CH₂ in 2), 2.6 (2H, t, CH₂COO),4.45 (1H, m, CHOH), 4.45 (2H, t, CH₂O—NO₂), 4.35 and 5.05 (2H, 2d,COCH₂O), 5.68(1H, s, olefin H).

EXAMPLE 1B

The product from Example 1A was also prepared using another syntheticroute.

Preparation of Hydrocortisone 4-bromobutanoate

Five portions of 4-bromobutanoylchloride (0.35 ml×5) and potassiumcarbonate (0.4 g×5) were added in 24 hours to a solution ofhydrocortisone (1 g) in CHCI₃ dried over P₂O₅ and stirred for 5 days.The solution was treated with water, the organic phase was separated,dried (Na₂SO₄) and deprived of the solvent at reduced pressure.

Preparation of Hydrocortisone 4-nitroxybutanoate (HCN)

AgNO₃ (0.2 g) was added to a solution of hydrocortisone 4-bromobutanoateprepared as above (0.23 g) in acetonitrile (70 ml) and-stirred for 48hours at room temperature.

The solution was deprived of the solvent at reduced pressure andchromatographed on silica gel using a solution of ethyl acetate andCH₂Cl₂ (3:7) as an eluant.

Cortisone 4-nitroxybutanoate was recovered from the head fractions andcharacterised by mass spectometry: M⁺ 493. The spectrum was the same asthat shown in Example 1A.

EXAMPLE 2

Evaluation of Safety and Activity

The products were administered in a 2%-by-weight carboxymethyl cellulosesuspension during in vivo tests, while a 0.1%-by-weightdimethylsulphoxide suspension was used for in vitro studies.

The test groups always included 8 samples (except when differentlystated in the examples) for adequate statistical evaluation, to becarried out when necessary according to common statistical procedures.

EXAMPLES 2A

Acute Toxicity Study

The acute toxicity of the product from Example 1A was roughly evaluatedby orally administering a single dose of substance to a group of 10 miceof the Swiss strain.

Death incidence and appearance of toxic symptoms were observed during aperiod of 14 days after the compound administration.

The animals showed no sign of apparent toxicity even afteradministration of a 50 mg/kg dose.

EXAMPLE 2B

Study of Antiarthritic Activity

Adjuvant arthritis was induced in male rats of Lewis strain, weighing170±15 g by intracaudal injection of 0.6 mg of Mycobacterium butyricum(Difco) suspended in 0.1 ml of mineral oil. The animals were treatedwith a vehicle made up of an intraperitoneal (i.p.) 2%-by-weightsuspension of carboxymethyl cellulose in water, with intraperitonealhydrocortisone of HCN (a suspension as described above) at doses of 5mg/kg or doses of 10 mg/kg, starting from the first day aftermycobacterium inoculation.

Arthritis development was assessed 21 days later. To the arthriticlesions an arbitrary score was assigned according to the followingscale:

-   -   hind limbs: 0 to 7 for each (0 for no lesions and 7 for most        severe lesions);    -   forelimbs: 0 to 4.5 for each (0 for no lesions and 4.5 for most        severe lesions);    -   tail: 0 to 5 (0 for no lesions and 5 for most severe lesions),    -   ears: 0 to 2 for each (0 for no lesions and 2 for most severe        lesions);    -   nose and eyes: 0 to 1 ofr each (0 for no lesions and 1 for most        severe lesions).

The results were expressed as a percentage of inhibition compared to thevalue obtained in the control group (animals treated withe the vehiclealone).

The result are shown in Table 1.

TABLE 1 STUDY OF ANTIARTHRITIC ACTIVITY OF COMPOUND HCN VERSUSHYDROCORTISONE IN RATS ANTIARTHRITIC ACTIVITY COMPOUND DOSE (mg/kg) (%)HYDROCORTISONE 5 40 HYDROCORTISONE 10 55 HCN 5 45 HCN 10 62

As shown by the results in Table 1, the test products were capable ofsimilarly inhibiting development of the arthritic process caused bymycobacterium. However, being the tolerability of HCN much higher thanthat of hydrocortisone (see ex 2C below), the results in terms ofactivity are much better in the case of HCN (see for comparison 40% ofantiarthritic activity obtained with 5 mg/kg hydrocortisone with respectto 62% obtained with 10 mg/kg HCN).

EXAMPLE 2C

Study of Gastric Tolerability (Safety)

Male Sprague-Dawley rats fasted for 24 hours were treated with 5 to 10mg/kg of intraperitoneal hydrocortisone or HCN.

Twenty-four hours later the animals were sacrified, the stomach wasremoved and tissue was grossly examined for the presence of lesions asdescribed by Del Soldato et al.: “The influence of fasting andcimetidine on the relationship between ulcerogenic and anti-inflammatoryproperties of cimetidine”, Br. J. Pharmacol. 67, 33–37, 1979. The degreeof severity of the disease was evaluated according to common methods andexpressed as arbitrary values. The results are shown in Table 2.

TABLE 2 STUDY OF GASTRIC TOLERABILITY OF COMPOUND HCN VERSUSHYDROCORTISONE IN RATS COMPOUND DOSE (mg/kg) GASTRIC TOLERABILITYHYDROCORTISONE 5 2.0 HYDROCORTISONE 10 3.5 HCN 5 0.5* HCN 10 1.2* Dataare expressed as arbitrary values according to the following scale: 0 =absent; 1 = mild lesions; 2 = moderate lesions; 3 = punctiform ulcers; 4= severe and numerous ulcers. *P < 0.05 (where P is probability)compared to corresponding value in group treated with hydrocortisone.

As shown in Table 2, the rats treated with hydrocortisone exhibited amarked disease in the gastrointestinal tract, varying in severity frommucosal erosion to ulcer involving the muscle layer, wall adhesions,ascites, peritonitis. In the other groups treated with the vehicle aloneor HCN, the damage was much lower or even absent.

EXAMPLE 2D

Study of Nitroxysynthetase Activity

The nitroxy-sinthetase inhibiting activity induced by lipopolysaccharide(LPS) was determined in rat neutrophils and stomach after administrationof one of the test compounds and compared with that obtained aftertreatment with the suspending vehicle only. Wistar rats fasted for 24hours before treatment received one of the test compoundsintraperitoneally (10 mg/kg) or LPS intravenously (caudal vein) (5mg/kg). Four hours later the animals were sacrificed. Blood forneutrophil isolation and stomach were removed.

Enzymatic activity was determined according to the method described byAssreuy et al.: “Feedback inhibition of nitric oxide synthase activityby nitric oxide”, Br. J. Pharmacol. 108, 833–7, 1993. The results-areshown in Table 3.

TABLE 3 STUDY OF NITROXYSYNTHETASE ACTIVITY IN COMPOUND HCN VERSUSHYDROCORTISONE IN RATS NITROXYSYNTHETASE COMPOUND DOSE (mg/kg/i.p.)ACTIVITY^(a) VEHICLE — 100  HYDROCORTISONE 10 55* HCN 10 62* ^(a)percent inhibition compared to group treated with vehicle alone *p < 0.05compared to corresponding value in group treated with vehicle.

As shown by Table 3, both test products proved to be very effective ininhibiting nitroxysynthetase compared to the group treated with thevehicle alone.

EXAMPLE 2E

Study of Bone Toxicity

Bone tissues (parietal bone from rat foetus) grown in vitro according tothe method described by Doherty et al. (“The effect of glucocorticoidson osteoblast function. The effect of corticosterone on osteoblast,expression of beta-I integrins”, Journal of Bone and Joint Surgery,Series A77/3, 396–404, 1995) was used. Hydrocortisone or HCN or thevehicle were incubated at concentrations of 100 nmol.

Ninety six hours later calcium content and bone dry weight weremeasured.

The results are shown in Table 4.

TABLE 4 EFFECT OF HCN AND HYDROCORTISONE ON BONE GROWTH IN RATS CalciumDRY TISSUE TREATMENT (nmol) Δ°% WEIGHT Δ°% VEHICLE — 310 160HYDROCORTISONE 10  70*  95* HCN 10 287 149 °Compared to initial value(incubation time zero) *P < 0.05 compared to values obtained in controlgroup (vehicle)

As shown in Table 4, a significant increase in tissue dry weight andincreased calcium were observed after incubation with the vehicle orHCN. After incubation with hydrocortisone, the calcium content decreasedand the bone dry weight did not increase. This shows that this treatmentwith hydrocortisone adversely affected bone growth.

EXAMPLE 2F

Study of Some Cardiovascular Parameters

The effect of the test products on some cardiovascular parameters wasstudied in conscious Long Evans rats (350 to 450 g) which wereappropriately monitored, as described by Gardiner et al.: “Influence ofdexamethasone on the regional haemodynamic responses tolipopolysaccharide in conscious rats: effect of the non-selectiveendothelin antagonist: SB 209670”, Br. J. Pharmacology 117, 49P, 1996.The animals were treated with the vehicle (physiologic saline solution,0,9% sodium chloride, s.c.) subcutaneous hydrocortisone or HCN (10mg/kg). Heart rate and blood pressure were recorded 4 hours aftertreatment.

Table 5 shows the data obtained as per-cent variation from controlvalues.

TABLE 5 STUDY OF COMPOUND HCN VERSUS HYDROCORTISONE IN SOMECARDIOVASCULAR PARAMETERS IN RATS HEART RATE^(a) BLOOD COMPOUND DOSE(mg/kg) (%) PRESSURE^(b) VEHICLE — 100  160 HYDROCORTISONE 10 89*  115*HCN 10 98  103 *P < 0.05 compared to group treated with vehicle^(a)per-cent change compared to value recorded in group treated withvehicle alone (324 ± 7 beats per minute) ^(b)per-cent change compared tovalue recorded in group treated with vehicle alone (101 ± 2 mm Hg)

The results in Table 5 show that the product of the invention HCN doesnot affect the cardiovascular parameters measured. On the contrary,hydrocortisone used in the known art shows significant pressure as wellas cardiac changes.

EXAMPLE 2G

Study of Angiostatic Activity in Rats

Male Wistar rats weighing 180 to 200 g were used according to theprocedure described by Andrade et al.: “Quantitative in vivo studies onangiogenesis in a rat sponge model”, Brit. J. Exp. Pathol. 68, 755–766,1987. The neovascularisation was evaluated in relation to blood flow byimplanting a small sponge in the subcutaneous tissue for 14 days anddetermining ¹³³Xe clearance. Briefly, an amount of ¹³³Xe equal to 10 μlwas injected into the sponge using a small polyethylene cannula. Theresidual radioactivity from implantation using a gamma ray detector andthe ¹³³Xe clearance for 6 minutes was measured as a percentage of theinitial value. The validity of this method for measuringneovascularisation was recently demonstrated by HU et al.: “Correlationof ¹³³Xe clearance, blood flow and histology in the rat sponge model forangionenesis. Further studies with angiogenic modifiers”, Lab. Invest.72, 601–610, 1995.

The test compounds were administered by the subcutaneous route at a doseof 10 mg/kg from day 1 to day 13 after implantation. ¹³³Xe was measuredat day 14 from subcutaneous implantation, the animals were thensacrificed and the weights of thymus and spleen were recorded.

Table 6 shows the data obtained regarding the effect of the testproducts on neovascularisation and on the weight of spleen and thymus.

TABLE 6 EFFECT OF HCN AND HYDROCORTISONE ON ¹³³Xe CLEARANCE AND WEIGHTOF SPLEEN AND THYMUS AT DAY 14 TREATMENT ¹³³Xe(%) SPLEEN (mg) THYMUS(mg) VEHICLE 42 663 ± 25 313 ± 28 HYDROCORTISONE 33 642 ± 32  185 ± 17*HCN  22* 673 ± 38 297 ± 31 *P < 0.05 compared to values obtained incontrol group (vehicle)

As evident, HCN proved to be capable of exerting a marked angiostaticeffect without changing the weight of spleen or thymus, differently fromthe reference product.

As it is clear from the whole of the data shown in Tables 1 to 6, thepharmacodynamic activity—anti-arthritic, immunosuppressive andantiangiogenic activities—and tolerability of the nitroderivative aresuperior than those of the cortoid from the known art.

EXAMPLE 3

Dexamethasone 21-(4-bromobutyrate) [II] Dexamethasone [I] 3.5 g 8.9 mmol4-Bromobutyryl chloride 4.06 ml 35 mmol Potassium carbonate 4.9 g 35mmol Tetrahydrofuran 70 ml

The solution of compound I in tetrahydrofuran is portionwise treatedwith 4-bromobutyryl chloride (0.81 ml×5) and potassium carbonate (0.98g×5) during 7 hours. The mixture is stirred overnight, the solvent isevaporated under vacuum and the residue is treated with ethyl ether andwater. The organic layer is separated, washed with water and dried withanhydrous sodium sulfate. After evaporation of the solvent, the residueis purified by silica gel flash column chromatography eluting witht.butyl methyl ether hexane 1-1 to give:

-   -   less polar compound 1.0 g;    -   derivative II 1.5 g (m.p. 184–187° C.; yield 31%)        TLC: t.butyl methyl ether-hexane 2-1.

Dexamethasone 21-(4-nitrooxybutyrate) [III] (compound DXN) Compound II1.5 g 2.7 mmol Silver nitrate 2.4 g 14.1 mmol Acetonitrile 250 ml

The mixture of compound II and silver nitrate in acetonitrile isrefluxed for 7 hours. After filtration of inorganic salts, the solventis evaporated under vacuum and the residue is treated with ethyl ether.The organic layer is twice washed with water, dried with anhydroussodium sulfate and evaporated under vacuum. The residue is poured intoethyl ether and filtered to give 1.27 g of pure compound III as a whitesolid (m.p. 183–185° C.; yield 90%)

TLC: t.butyl methyl ether-hexane 2-1.

The following forms are enclosed:

-   -   synthetic scheme;    -   NCX 1005 batch 1;    -   NCX 1005/1 analysis.

EXAMPLE 4

Study of the Activity on Leucocyte Accumulation

Male Swiss albino mice (27–33 g) maintained on a standard chow pelletdiet and tap water ad libitum were used. The experiment was done aspreviously described by Perretti et al. (Perretti M., Solito E., ParenteL., “Evidence that endogenous interleukin-1 is involved in neutrophilmigration in acute experimental inflammation in rats and mice”, AgentsActions, 35, 71, 1992). Animals were pretreated with zymosan (1 mg/0.5ml) i.p. at time 0. Two hours later DEXAMETHASONE (1 mg/kg) (Ex3-I), DXN(Ex3-III)(1 mg/kg) or phosphate buffered saline (PBS) was givenintravenously. The animals were sacrificed at 4 and 24 h the lavagefluids were collected and differential cell counts were performedfollowing staining in Turk's.

Table 7 reports results obtained on the inhibitory effect of the testedcompounds on zymosan-induced leucocyte migration in mice. As can beobserved the nitroderivative steroid is much more active thandexamethasone.

TABLE 7 Inhibition of neutrophil and monocyte recruitement byDEXAMETHASONE and DXN (1 mg/kg) given 2 h i.v. after zymosan (1 mg/0.5ml) i.p. mono-m∪ × 10⁶/ PMN × 10⁶/mouse mouse treatment (time 4 h) %reduction (time 24 h) % reduction vehicle 10.1 ± 1.0  . . . 8.8 ± 1.3 .. . DXN 4.5 ± 0.3 55.4 4.5 ± 0.6 48.8 DEXAMETHASONE 6.4 ± 0.4 36.6 6.3 ±0.2 28.4

EXAMPLE 5

Study of the Anti-proliferative Activity in Human Airway Smooth MuscleCells

Human airway smooth muscle cells were cultured by standard explantmethods. Tissues were collected into sterile pots containing PBS andpenicillin and streptomycin. Under sterile tissue culture conditions,tissues were cut into small pieces (approximately 1 mg weight) andplaced into standard medium containing 20% fetal calf serum (FCS) forseveral days (medium changed every 2–4 days). ³H-thymidine was measuredin the DNA fraction of cells cultured into 48 well plates. Cells werecultured to confluence in the medium containing 10% FCS. Cells weredeprived of serum for 24 h before the addition of 10% FCS, together withdifferent concentration of, steroids. After 24 h, ³H-thymidine was addedto the cells for 4 h. Cells were washed with phosphate buffered salineand ethanol. The DNA was extracted with sodium hydroxide solution andthe ³H material counted by scintillation. The data representobservations made in triplicate wells from smooth muscle cultured fromone healthy lung donor. Table 8 reports results obtained on theinhibitory effect of the tested compounds on human airway smooth cellproliferation. As can be observed the nitroderivative steroid is muchmore active than dexamethasone.

TABLE 8 Inhibition of human airway smooth cell mitogenesis by differentconcentrations of DEXAMETHASONE and DXN Concentration ³H-thymidineTreatment (logM) (CPM × 1000) DEXAMETHASONE −5 14.1 −7 15.0 DXN −5 10.8−7 12.6

CONCLUSIONS

As can be observed from results reported above, both activity and safetyof the new nitroderivatives are better than those owned by the precursorsteroids.

1. A compound of formulaB—R″—X₁—NO₂ or their esters or salts, wherein B—R″ has the followingstructure:

R″ is —(CO-L)_(t)—(X)_(t1) wherein in the place of H in the CH group orH₂ in the CH₂ group there may be the following substituents: at position1–2: a double bond; at position 2–3

at position 2, Cl or Br; at position 3, oxo, —O—CH₂—CH₂—Cl, or OH; atposition 4–5, a double bond; at position 5–6, a double bond; at position6, Cl, F CH₃, or CHO; at position 7, Cl; at position 9, Cl or F; atposition 11, OH, oxo or Cl; at position 16, CH₃, OH, or ═CH₂; atposition 17, OH, CH₃, OCO(O)_(ua)(CH₂)_(va)CH₃, or

 wherein ua is an integer equal to 0 or 1 and va is an integer from 0 to4; at position 16–17,

R and R′ are equal or different one from the other and may be hydrogenor linear or branched alkyls having from 1 to 4 carbon atoms, wherein inR″ t and t1 are integers where t is equal to 1, t1 equals 0, 1; whereinbetween B and X₁ there is an ester or amide linkage; the bivalentbridging member L is selected from the group consisting of(CR₄R₅)_(na)(O)_(nb)(CR₄R₅)_(n′a)(CO)_(n′b)(O)_(n″b)(CO)_(n′″b)(CR₄R₅)_(n″a),wherein na, n′a, and n″a are equal to or different one from the otherand are integers from 0 to 6, nb, n′b, n″b and n′″b are equal to ordifferent from each other and are equal to 0 or 1; R₄ and R₅ are equalor different one from the other and are selected from the groupconsisting of H, linear or branched alkyls having 1 to 5 carbon atoms, Xis equal to Xo where Xo is O, NH, NR_(1c) where R_(1c) is a linear orbranched alkyl having from 1 to 10 carbon atoms; X₁ is selected from thegroup consisting of

wherein n₃ is an integer from 0 to 3; and

wherein B is a residue of flunisolide.
 2. Pharmaceutical compositioncomprising a compound according to claim 1 and a pharmaceuticallyacceptable carrier.